Method of improving surface morphology of (Ga,Al,In,B)N thin films and devices grown on nonpolar or semipolar (Ga,Al,In,B)N substrates

1. A method for fabricating III-nitride film, comprising:

growing a III-nitride film having a planar top surface, wherein the planar top surface:

is a nonpolar or semipolar plan, and

has a root mean square surface roughness, as-grown, of less than 0.5 nanometers over an area of at least 100 micrometers squared.

2. The method of claim 1 , further comprising growing the film on a III-nitride substrate or template with a miscut away from a low index crystal orientation.

3. The method of claim 2 , wherein the substrate or template is an m-plane substrate or template, the miscut has a miscut angle toward a [000-1] direction between 0.75° and 1.50°, and the III-nitride film is grown on a surface of the miscut.

4. The method of claim 1 , further comprising growing the film using a carrier gas, wherein at least a portion of the carrier gas is comprised of an inert gas and the inert gas is comprised of one or more of the following: N 2 , He, Ne, Ar, Kr, or Xe.

5. The method of claim 1 , wherein one or more device layers are deposited on the top surface of the film, and the device layers are grown with at least a portion of the carrier gas being comprised of H 2 .

6. The method of claim 5 , wherein the device layers include one or more p-type doped layers of the device and the p-type doped layers are grown with at least a portion of the carrier gas being comprised of H 2 .

7. A nonpolar or semipolar III-nitride film, comprising:

a planar top surface, wherein the planar top surface:

is a nonpolar or semipolar plane, and

has a root mean square surface roughness, as-grown, of less than 0.5 nanometers over an area of at least 100 micrometers squared.

8. The film of claim 7 , wherein the area has an absence of striations.

9. The film of claim 7 , wherein the top surface is atomically smooth with a surface roughness on the order of a diameter of Ga,Al,In,B, and N atoms.

10. The film of claim 7 , wherein the root mean square surface roughness is less than 0.25 nanometers over the area.

11. The film of claim 7 , wherein the film is deposited on a surface of an m-plane substrate, and the surface of the m-plane substrate is a miscut with a miscut angle between 0.75° and 1.50° toward a [000-1] direction.

12. The film of claim 11 , wherein the substrate is a Gallium Nitride substrate.

13. The film of claim 7 , wherein the area of the top surface is smoother than a surface characterized pyramidal hillocks having a density of 8.4×10 2 cm −2 , a size of 10 micrometers and a slope angle of 0.1°.

14. The film of claim 7 , wherein the area of the top surface is smoother than a surface characterized pyramidal hillocks having a density of 1.1×10 6 cm −2 .

15. The film of claim 7 , wherein the film is an m-plane GaN film and the top surface is an m-plane of the m-plane GaN film.

16. The film of claim 7 , wherein device layers grown on the film have a top surface that is at least as smooth as the top surface of the film.

17. The film of claim 7 , wherein the area is optically smooth and has an absence of identifiable non-planar surface undulations or features as measured using an optical microscope and with light wavelengths between 400 nanometers and 600 nanometers, the film is a substrate for epitaxial deposition of one or more device layers that emit light having an output power of at least 2 milliwatts at 20 milliamps drive current, and the drive current is direct current.

18. The film of claim 7 , wherein the plane is a nonpolar plane and the film is a nonpolar film.

19. The film of claim 7 , wherein the plane is a semipolar plane and the film is a semipolar film.

20. The film of claim 7 , wherein the film is Gallium Nitride.

21. The film of claim 7 , wherein the film is grown on a Gallium Nitride substrate.